MEDULLARY CHEMORECEPTOR PHYSIOLOGY

髓质化学感受器生理学

基本信息

批准号：
3340821
负责人：
JEROME M ADAMS
金额：
$ 6.63万
依托单位：
UNIVERSITY OF VIRGINIA
依托单位国家：
美国
项目类别：
财政年份：
1983
资助国家：
美国
起止时间：
1983-09-01 至 1988-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/3340821
关键词：
acidity /alkalinity anions arterioles carbon dioxide transport cerebrospinal fluid chemoreceptors homeostasis ion transport mathematical model medulla oblongata microelectrodes neurophysiology perfusion phrenic nerve pulmonary respiration respiration regulatory center respiratory gas level

项目摘要

Rational treatment of respiratory disease, especially acute respiratory failure and CO2 retention in chronic diseases, is based on the understanding of CO2 control of breathing. The medullary chemoreceptors play a crucial role in regulating breathing but the mechanisms governing their activity are not established. The relation between hydrogen ion activity in medullary chemoreceptor tissue and phrenic nerve activity will be studied in anesthetized rats and cats by measuring tissue pH with a pH microelectrode during changes of arterial PCO2 and PO2. The possibility of trans-arteriolar CO2 exchange during high flow CSF perfusion will be tested by measuring tissue pH while changing arterial and CSF perfusate PCO2 in the same and in opposing directions. By measuring local tissue perfusion with a servo controlled temperature probe, with simultaneous measure of tissue pH, the response of blood flow in the chemoreceptor tissue to changes of PO2 and PCO2 and its relation to tissue hydrogen ion activity will be studied. The effect on tissue pH of the carrier mediated exchange of HCO3- across cells will be studied by measuring tissue pH response to altering arterial PCO2 before and after pharmacologic block of the HCO3 carrier. Yamamoto's hypotheses concerning the generation of CO2 by respiratory neuron activity and consequent chemoreceptor stimulation will be tested by measuring chemoreceptor pH during stimulation of the carotid sinus nerves. These studies should provide evidence to reject or accept hypotheses of chemoreceptor mechanisms which are of cardinal importance.

合理治疗呼吸系统疾病，特别是急性呼吸道疾病慢性疾病中的衰竭和二氧化碳潴留是基于了解二氧化碳对呼吸的控制。髓质化学感受器在调节呼吸方面发挥着至关重要的作用，但控制机制他们的活动尚未确定。氢离子与氢离子的关系髓质化学感受器组织的活动和膈神经的活动将通过使用 pH 值测量组织 pH 值，对麻醉的大鼠和猫进行研究微电极在动脉 PCO2 和 PO2 变化期间。的可能性将测试高流量脑脊液灌注期间的经小动脉二氧化碳交换通过在改变动脉和脑脊液灌注液 PCO2 的同时测量组织 pH 值相同和相反的方向。通过测量局部组织灌注带伺服控制温度探头，同时测量组织 pH 值，化学感受器组织中血流对 pH 值的反应 PO2和PCO2的变化及其与组织氢离子活性的关系将被研究。载体介导的交换对组织pH的影响将通过测量组织 pH 值响应来研究 HCO3- 跨细胞的情况在 HCO3 药理阻滞之前和之后改变动脉 PCO2 载体。山本关于二氧化碳生成的假说呼吸神经元活动和随后的化学感受器刺激将通过在刺激颈动脉期间测量化学感受器 pH 值进行测试窦神经。这些研究应该提供拒绝或接受的证据化学感受器机制的假设至关重要。